RESUMO
The isoflavones daidzein and genistein are natural compounds which have anti-inflammatory and photoprotective activities, and may be effective in the repair of ultraviolet (UV)-induced photodamage. In this study, an alcoholic solution of aglycone isoflavones with a genistein:daidzein ratio of 1:4 [Rottapharm (RPH)-aglycone] was examined for its effects on the repair of DNA damage induced by a single dose of UVB irradiation (20 mJ/cm(2)). For this purpose, human skin cells were first UVB-irradiated and then treated with RPH-aglycone. Comet assay analysis was used to estimate the UVB-induced DNA damage at different time points after treatment by measuring the tail moment parameter. We found that treatment with 10 µmol/L RPH-aglycone solution resulted in a significantly reduced tail moment at 1h after treatment, and 34-35% enhancement of damage repair at 4 h after treatment. These results suggest that isoflavone aglycones are protective against UVB-induced DNA damage.
Assuntos
Anticarcinógenos/farmacologia , Dano ao DNA/efeitos dos fármacos , Células Epidérmicas , Células Epiteliais , Genisteína/farmacologia , Isoflavonas/farmacologia , Raios Ultravioleta/efeitos adversos , Células Cultivadas , Ensaio Cometa , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/efeitos da radiação , Humanos , Envelhecimento da Pele/efeitos dos fármacosAssuntos
Ciclo-Oxigenase 2 , Queratinócitos , Linhagem Celular , Niacina , Niacinamida , Raios UltravioletaRESUMO
The CaCo-2 cell line is used to study the molecular mechanisms underlying differentiation of intestinal epithelial cells. These cells undergo a gradual differentiation process that is growth-related and depends on cellular density. CaCo-2 cells acquire a morphological polarity and express such markers of mature enterocytes as sucrase-isomaltase, apolipoproteins, alkaline phosphatase, and H-ferritin. Because the NF-Y transcription factor is required for H-ferritin gene expression, we investigated whether it is involved in the expression of the other CaCo-2 differentiation markers. We observed that subunit NF-YA increases during CaCo-2 differentiation and that the constitutive expression of NF-YA, obtained in stably transfected CaCo-2 cells, results in the expression of differentiation markers. In fact, sucrase-isomaltase, apolipoprotein A1, and H-ferritin were constitutively expressed in NF-YA-transfected cells and their levels did not increase during prolonged culture, while these markers were not expressed in mock-transfected CaCo-2 cells or transfected with an inactive NF-YA expression vector until the onset of differentiation.